Elastomer drive couplings are transmission devices that connect between a driving member and a driven member, such as in a drive train, to provide misalignment accommodation, torque carrying capability and appropriate stiffness for vibration isolation. Couplings are used, for example, in a drive train between an engine and a unit to be rotated, such as a compressor. The torsional stiffness of the coupling is designed to minimize torsional vibrations that may cause damage to the drive train components.
Examples of prior art couplings can be found in U.S. Pat. No. 2,444,904 to Worley, U.S. Pat. No. 2,504,750 to Strachovsky, U.S. Pat. No. 4,050,266 to Bergman, U.S. Pat. No. 3,321,935 to Wildhaber, U.S. Pat. No. 3,183,684 to Zeidler, U.S. Pat. No. 4,240,763 to Moore, U.S. Pat. No. 4,913,671 to Gavriles and U.S. Pat. No. 5,435,784 to Mark.
Certain ones of these prior art couplings have general deficiencies in performance and/or durability. For example, in the spider coupling described in the '784 Mark patent, the rubber blocks 24 are not bonded to the inner member lugs 22, thus they do not effectively transfer loads to the outer member drive ring 10. Further, the rubber blocks 24 will have the tendency to abrade against the drive ring's trapezoidal openings 14 due to slight angular and/or parallel misalignment. As a result, the drive train including the Mark's '784 device must be torn down periodically in order to replace the rubber blocks 24. Accordingly there has been a long felt, and unmet need for a coupling capable of transmitting large torques, accommodating misalignments and which exhibits extended durability such that replacement intervals are decreased.